Gas Explosion Effects on Offshore Structures

摘要

Gas explosion is a rare but severe event on offshore production facilities. Its impact is a severe load on the structure. This paper identifies the key characteristics of these forces and factors governing the severity of an explosion, and examines the effects of the direct over-pressure loading generated by an offshore explosion on walls, floors and ceilings. The gases venting from the explosion can also generate high drag loads on equipment, pipe work , structural elements etc. sited in the vent areas. Two cases are considered, a module where the dominant loading effects are due to the direct over-pressure and an FPSO where the drag load has a considerable effect on equipment on the deck. This paper discusses the two types of loading mechanism, also the range of analysis methods available to the designer is considered from a simple quasi-static approach to a sophisticated finite element model. Finally, the structural response implications of the variability of the pressure-time histories obtained from both CFD simulations and full scale tests is discussed with a view to setting a design value for blast over-pressures.